Grass seed, fertilizer, and other substances for lawn care are often dispensed in broadcast fashion. Stated otherwise, the seed or other subject is spread substantially uniformly on the surface of the earth. Hand spreading of seed and the like is time consuming and inaccurate as to uniformity of spreading. Accordingly, various types of mechanical broadcast lawn spreaders have been developed.
One type of lawn spreader is provided with wheels and a handle for manually moving the spreader across the surface of the earth. One form of such spreader utilizes a narrow slot extending transversely of the direction of motion of the device across the earth. The narrow width of the slot is variable to determine the density of spreading. Another specific form of the generic type spreader mentioned above utilizes a spinning disc beneath the upper portion or hopper of the device. An aperture is provided at the bottom of the hopper, and a closure member is provided which may be opened or closed to different degrees to determine the rate of flow of seed or the like. When seed or the like hits the surface of the spinning disc it is centrifuged off of the disc and falls on the ground in substantially uniform distribution.
In the prior art type of broadcast lawn spreader having a rotating disc for centrifuging the dispensed material it is known to provide a rectangular opening in or near the bottom of the hopper overlying the spinning disc. The disc is spun or rotated by means of gearing from the wheels, and the speed at which the disc turns is determined by the speed at which the operator moves the spreader or apparatus.
The density or rate of dispensing particulate material from the hopper to the spinning disc is regulated by means of a sliding plate or door across the aperture, connected by means of a flexible wire or cable to a control at the top of the handle. The operator thus must remove one hand from the handle to operate the control.
In order to determine the maximum rate of dispensing, and thereby to attain the desired uniformity of material spread broadcast upon the surface of the earth it has been known to provide an adjustable limit stop interconnected with the sliding plate and the wire and in the vicinity of the sliding plate. This presents some drawbacks in that the positioning of the limit stop cannot be controlled while the spreader is moving without considerable risk of spilling the material to be spread. Spilling of fertilizer is dangerous in that too much fertilizer will kill grass. Thus, the operator must stop, lean over and then make some sort of adjustment of the limit stop. This is undesirable, because it does not allow the operator any chance to observe the density of broadcasting of material while the spreader is moving. It is rather a cut-and-try procedure, since the stop has to be adjusted and the spreader operated, followed by stopping, readjustment, and re-operating of the spreader.